package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.List;
import java.util.Set;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.BLOG_LIKED_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    @Resource
    private IUserService userService;

    @Autowired
    private StringRedisTemplate stringRedisTemplate;



    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();
        // 查询用户
       // records.forEach(this::extracted);
        records.forEach(new Consumer<Blog>() {
            @Override
            public void accept(Blog blog) {
                extracted(blog);
                isliked(blog);
            }
        });
        return Result.ok(records);
    }

    @Override
    public Result likeBlog(Long id) {
        Long userId = UserHolder.getUser().getId();
        String key=BLOG_LIKED_KEY+id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if (score!=null) {//  则代表已经点过赞
            //取消点赞
            boolean isSuccess = update().setSql("liked=liked-1").eq("id", id).update();
            if (isSuccess) {
                stringRedisTemplate.opsForZSet().remove(key, userId.toString());
            }

        }else {  //不然就是没点过赞
            boolean isSuccess = update().setSql("liked=liked+1").eq("id", id).update();
            if (isSuccess){
                stringRedisTemplate.opsForZSet().add(key,userId.toString(),System.currentTimeMillis());
            }
        }
        return Result.ok();
    }

    @Override
    public Result queryBlogBlikes(Long id) {

        String key=BLOG_LIKED_KEY+id;
        Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if (top5==null|| top5.isEmpty()){
            return Result.ok();
        }
        List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());

        String idStr = StrUtil.join(",", ids);
        // 3.根据用户id查询用户 WHERE id IN ( 5 , 1 ) ORDER BY FIELD(id, 5, 1)
        List<UserDTO> userDTOS = userService.query()
                .in("id", ids).last("ORDER BY FIELD(id," + idStr + ")").list()
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());

        return Result.ok(userDTOS);

    }

    private void extracted(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }


    @Override
    public Result queryBlogById(Long id) {
        Blog blog = getById(id);
        extracted(blog);
        isliked(blog);
        return Result.ok(blog);
    }

    private void isliked(Blog blog) {
        if (UserHolder.getUser()==null){
            return;
        }
        Long userId = UserHolder.getUser().getId();
        String key=BLOG_LIKED_KEY+blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if (score!=null) {// 则代表已经点过赞
           blog.setIsLike(true);
        }else {  //不然就是没点过赞
           blog.setIsLike(false);
        }

    }
}
